BBC Radio 1Xtra Live was cut short last night after a man was slashed with a knife backstage.
The show at the Arena Birmingham was due to include performances from Wizkid, Aitch, DaniLeigh and French Montana among others before it was suddenly called off.
West Midlands Police said they were alerted to assault in the backstage area by the venue's security at around 10pm.
Officers said the victim suffered a slash wound and did not require hospital treatment.
BBC Radio 1Xtra said in a statement: “Following an isolated serious incident, we have had to stop 1Xtra Live in Birmingham. We are co-operating fully with the police to establish what has happened.
“We’re sorry to everyone who attended 1Xtra Live in Birmingham for the early finish, however the health and safety of everyone involved is always our top priority.
A spokesperson would not comment on the identity of the injured man.
Radio 1Xtra is a digital urban contemporary and Black music radio station run by the BBC.
Its Birmingham event, which ran on Saturday, was was billed as an "unmissable night", with tickets had sold out at the 15,800-capacity arena.
The gig was broadcast live across 1Xtra and Radio 1, but the stream ended when the event was pulled.
West Midlands Police is appealing for information following the alleged assault.
Anyone with information is asked to call Crimestoppers anonymously on 0800 555 11, quoting crime number 20BW/236014J/19.
